Transmissions are sufficiently known in the prior art for use in vehicles, tool machines and devices in many technical areas. Gear transmissions are especially widespread and will be examined in detail in the following in the course of the description of the invention.
Transmissions allow shifting by changing translation ratios between gears, which result in a changing of the speed and of the torque. In spur gear transmissions a drive shaft and a driven shaft are arranged parallel to one another. Relatively simple such transmissions for tool machines have at least one drive arrangement and a driven arrangement on which power gears in the form of spur gears can be arranged, wherein the drive arrangement and the driven arrangement can be shifted in such a manner relative to one another that at least two different pairings of power gears can be produced that deliver different translations as a function of the diameter ratio and therefore of the ratio of the number of teeth.
It is necessary in such simple transmissions to completely brake and stop a system comprising the transmission so that the translation ratio can be changed in the case of teeth moved relative to each other by a relative shifting of the drive arrangement and of the driven arrangement without damaging the power gears.
DE 20 2010 001 876 U1 discloses a transmission with a drive arrangement comprising a first power gear and a second power gear between which a first ratchet gear constructed as a bevel gear is arranged in a flush manner. A driven arrangement comprises a third power gear that can be brought into engagement with the first or the second power gear. A switching device moves the third power gear in such a manner that it is engaged with the first or the second power gear so that a switching occurs by moving the third power gear.